This poem and its variations, were written by Cora Unashamed screenwriter, Anne Peacock.
About 18 minutes into the film, we hear Joe's voice ...

I will see you in the cornfields. I will see you where the bluegrass grows.
I will hear you when I listen as the soft wind blows.
I will see you in the moonlight. I will see you in every star.
I will see you wherever I wander, no matter how far.

And I will keep looking. And I will keep listening.
And I will keep remembering long after the days have gone...
That our love, my dearest, will always live on.

Later, at Jessie's deathbed, Cora says:

When you love someone they're never far away, because they're always with you. That's because love has no time or space. It just continues on forever.

I will see you in the cornfields. I will see you where the green grass grows.
I will hear you when I listen, wherever the soft wind blows.
I will see you in the moonlight. I will see you in every star.
I will see you wherever I wander... no matter how far.

And I will keep listening and I will keep looking
And I will keep remembering, long after the days are gone.
For our love, my dearest, will always live on.